1. Field of the Invention
The present invention relates in general to a coil which is suitable for use in detecting a position indicated by a position indicator in accordance with an electromagnetic induction method (hereinafter referred to as “an indicated position” for short), a position indicator, a position detecting device, and a coil winding method.
2. Description of the Related Art
Heretofore, the techniques disclosed in Japanese Patent Laid-Open Nos. Sho 63-70326 (hereinafter referred to as Patent Document 1) and Hei 7-175572, respectively, have been known as ones each relating to a position detecting device for detecting an indicated position in accordance with an electromagnetic induction method. These techniques are such that a coil is provided in a position indicator and a sensor coil is provided in the position detecting device, and under this condition, a signal based on an electromagnetic wave is transmitted and received between the position detecting device and the position indicator, whereby the position detecting device detects the indicated position.
In recent years, with the advancement in practical realization of a liquid crystal display device, it has become desirable to have a position detecting device in which the position detecting device is combined with the liquid crystal display device, such that a position at which the drawing is desired to be carried out is directly indicated with a pen, thereby making it possible to input drawing information or the like. A position detecting device disclosed in Japanese Patent Laid-Open No. 2007-257359 (hereinafter referred to as Patent Document 2), for example, is known as such a position detecting device. With this position detecting device, a magnetic field component of a signal generated by a coil of a position indicator is detected by a sensor coil disposed in a front surface of a liquid crystal panel.
In addition, a construction of the position indicator used in the technique disclosed in Patent Document 2 is described in Japanese Patent Laid-Open No. 2007-164356 (hereinafter referred to as Patent Document 3). Each of the techniques disclosed in Patent Documents 2 and 3, respectively, is such that a power source is provided in the position indicator and an AC magnetic field is generated from a coil, and thus an indicated position on a liquid crystal panel is detected in accordance with an electromagnetic induction method between the AC magnetic field and the sensor coil made of a transparent conductive material (ITO film) and disposed on a front surface of the liquid crystal panel.